Valve mechanism for rock drills



Patented Apr. 30, 1935 UNITED STATES PATENT GFFICE VALVE MECHANISM FOR ROCK DRILLS GeorgeH. Fuehrer, Easton, Pa., assignor to In gersoll-Rand Company, Jersey City, N. J., a corporation of New Jersey Application January 8, 1932, Serial No. 585,514

2 Claims. (Cl. 121-20) This invention relates to fluid actuated rock the ratchet ring U a Carries DaWlS X for drills, and more particularly to a valve mechaeas men with t e h Y on he ratche rin U o nism for effecting the distribution of the pressure rotate the drill steel R, the p n D d the uck fiuid to the percussive element of the drill. members and P.

5 One object of the invention is to effect a, rapid In accordance with the present invention the 5 distribution of pressure fluid to the piston chamvalve mechanism, emp y r effecting e ber of the drill for actuating the piston. tribution of pressure fluid to the ends of the piston Another object of the invention is to effect a C b r C, Co prises a valve chest Z which may positive action of the distributing valve, and still extend longitudinally of the cylinder B and of 1 another object is to accelerate or decelerate the which it may form a part. Within the valve chest action of the distributing valve at will. Z is a bore which extends from one end of the Other objects will be in part obvious and in valve chest to the other to serve as a distributing part pointed out hereinafter. valve chamber 12 for the accommodation of a dis- In the drawing accompanying this specification tlibuting valve 0- 5 and in which similar reference characters refer Intermediate the ends of the Valve chest Z is a 15 to similar parts, supply connection it through which pressure fluid Figure l is a sectional elevation of a rock drill may be admitted into an enlarged recess 6 in the equipped with valve mechanism constructed in valve chamber 1) and being located adjacent the accordance with the practice of the invention, supply connection it.

and Closures are provided for the front and rear 20 Figure 2 is a transverse view taken through Figends of the valve chamber 12 in the form of plates ure 1 on the line 22 looking in the direction 1 and g, respectively, and said plates are bored for indicated by the arrows. the reception of a bolt h which extends coaxially Referring more particularly to the drawing, through the valve 0 and is provided with a nut 7' A designates, in general, a rock drill comprising a whereby the plates f and 9 may be clamped fixedly cylinder B having a piston chamber 0 to accomin position. Y 7

modate a reciprocatory hammer piston D. The Leading from the valve chamber 1) at a point cylinder B is provided with the usual front and forwardly of the enlarged portion e and opening back heads E and F, respectively, which may be into the front end of the piston chamber C is a secured to the cylinder in any well known front inlet passage It through which pressure fluid 3O manner. flows to drive the piston D rearwardly, and from A closure is provided for the front end of the a point rearwardly of the enlarged portion e of piston chamber 0 in the form of a front cylinder the valve chamber leads a rear inlet passage 0 Washer G which extends partly into the cylinder which opens into the rear end of the piston charm- B and the front head E and has a bore H through her C to admit pressure fluid thereinto for driv- 35 which eXteIldS S dab y a extension J of the p ing the piston D forwardly on its Working stroke. t The extension J is provided with a series The valve chest is further provided with front of flutes K to interlock slidably with introverted and rear xh st ports p and q, respectively, and ribs L of a chuck member 0 arranged within the said exhaust ports are arranged between the inlet front head E. In the flOIlll head E and forwardly passages and the ends of the valve chamber b, 40 of the chuck member 0, wher with it may be suit- The front and rear ends of the valve chamber ably interlocked, is a second chuck member P hav t t t pressure chambers and s resmcmg a bore Q for the reception of Working imple tively. Each pressure chamber has a main exment: such as a drill Steel R against which the haust port t which is so located that it will be hammer pistonD Strikesuncovered by the adjacent end of the valve 0,

In the rear end of the cylinder B is an enlarged g I q preferably immediately before the end of the bole s to accommodate back cylinder wamer T stroke of the valve. Between the exhaust ports t which acts as a closure for the rear end of the piston chamber C. The back cylinder washer T and t e of B Valve chambet b also serves as a seat for a ratchet ring U arranged presswn relief poms u located a Shght dlstame 5 in the back head R from the ends of the valve chamber to provide Extending through th back cylinder Washer T an avenue of escape for some of the air in the is a rifle bar V wherewith the piston D is slidably P u am e a d t us p v nt the formainterlocked in a well known manner. The rifle tion of sufficient compression to retard the action bar V carries the usual head W which lies within of the valve before the valve has reached a posi- 55 tion to communicate the ends of the cylinder with pressure fluid supply.

In order to assure a nicely timed, rapid and positive action of the valve 0, the rock drill is provided with additional valve mechanism designated, in general, by v to control the flow of pressure fluid to the pressure chambers r and s for actuating the valve 0. For the sake of convenience of illustration the valve mechanism 0 is arranged at the rear end of the valve chest Z. It comprises a valve chest w which seats upon the plate g and is bored to accommodate the bolt h which serves to secure the valve chest w, as well as the plates f and g, in position. The valve chest 20 is suitably recessed to form therein a valve chamber as for the accommodation of a control valve y, as for instance of the oscillatory plate type, which rocks on its transverse median line 2 and has a pair of opposed wings 2 and 3 on opposite sides of the transverse median line z. The valve y' has a bore 4 arranged coaxially in the valve to receive the bolt h which extends therethrough to hold the valve against lateral movement in the valve chamber :12. Preferably the valve 1/ is provided in its periphery and on the transverse median line a with notches 5 to engage pins 6 seated in the valve chest w for holding the valve y against rotary movement in the valve chamber.

The pressure fluid distributed by the valve 11 is conveyed into the pressure chamber 3 through an inlet passage 1' in the plate g to act against an actuating surface 8 on the end of the valve c lying in the pressure chamber 5, said passage 1 being located beneath the wing 2 of the valve y whereby it is controlled. Similarly, in the plate g is a front inlet passage 9 which is controlled by the wing 3 of the valve 3 and extends forwardly through the bolt 71. and opens into the pressure chamber 1.

The pressure fluid distributed by the valve y is conveyed to the valve chamber a: through a supply passage it communicating at one end with the enlarged portion e of the valve chamber 2) and extending through the valve chest Z, the plate g and the valve chest w and opening into the valve chamber :2. A portion of the passage H as for instance the portion ll lying in the plate g may be somewhat enlarged, and a needle valve l2 threaded into the valve chest w extends through the enlarged portion H into the adjacent portion of the passage l0 lying in the valve chest Z to control the flow of pressure fluid through the passage it] into the valve chamber x. The needle valve l2 may be provided with a suitable lock nut l3 to seat against the valve chest to for holding the needle valve [2 securely in position.

The valve 0, selected for illustrative purposes, comprises front and rear end heads E4 and I5 and intermediate flanges l6 and I7. Between the flanges l6 and H is an annular groove l8 through which pressure fluid may flow to the inlet passages k and o. The head l4 and the flange It are separated by an annular groove 59 which, in one limiting position of the valve 0, establishes communication between the inlet passage is and the exhaust port p. A groove 20, similar to the groove I9, is formed between the flange El and the head 45 to afford communication between the rear inlet passage 0 and the exhaust port q.

The operation of the device is as follows: With the valve 0 in the'rearmost position and the wing 2 of the valve 1/ raised as illustrated, pressure fluid flows from the enlarged portion e through the annular groove I 8 and the rear inlet passage 0 to the back end of the piston chamber C to drive the piston D forwardly on its working stroke. At the same time pressure fluid will flow from the valve chamber a: through the inlet passage 7 into the pressure chamber s to act against the actuating surface I5 and will drive the valve 0 forwardly.

After the head M of the valve 0 covers the exhaust port t the air in the pressure chamber 1' will be expelled to the atmosphere through the port u, instead of being compressed, so that the valve 0 may quickly complete its forward stroke and establish communication between the enlarged portion e and the inlet passage is. When the valve 0 reaches this position pressure fluid will flow into the front end of the piston chamber C and will drive the piston D rearwardly.

As the valve 0 nears the foremost limiting position in the valve chamber b the head l5 uncovers the exhaust port' if to permit the pressure fluid to exhaust from the pressure chamber s. Upon the exhaust of pressure fluid from the pressure chamber s the air flowing over the raised wing 2 of the valve 1 will tip the valve y to seat the wing 2 upon the plate g and to raise the wing 3 of the valve 3!. With the valve y in the new position pressure fluid flows over the wing 3 and throughthe passage 3 into the pressure chamber r to return the valve 0 to its initial position so that pressure fluid will again flow from the enlarged portion e of the valve chamber into the rear end of the .piston chamber (3'.

By suitably adjusting the needle valve I2v the volume of pressure fluid flowing to the valve chamber r may be conveniently controlled. If the nature of the rock being drilled is such as to require a reduction in the speed of the hammer piston D the needle valve l2 may be adjusted to reduce the flow area of the passage It. In consequence of this reduction the time required for charging the pressure chambers r and s will be somewhat lengthened and the action of the valves 3 and c will therefore be retarded. On the other band, should the material being drilled be of such a nature as to require blows delivered in rapid succession to the drill steel R the needle valve I2 may be adjusted to increase the flow of pressure fluid to the valve chamber. With an ample supply of pressure fluid flowing to the valve chamber a: the action of the valve y and, therefore, of the valve 0 will be increased with a resulting increase in the speed of the piston D.

I claim:

1. In a fluid actuated rock drill, the combination of a cylinder having a piston chamber and a piston therein, a valve chest having distributing and control valve chambers, a distributing valve in the distributing valve chamber to control the distribution of pressure fluid into the piston chamber, a' control valve in the control valve chamber, opposed pressure chambers in the distributing valve chamber, inlet passages controlled by the control valve conveying pressure fluid from the control valve chamber to the pressure chambers for actuating the distributing valve and conveying compression from the pressure chambers to the control valve chamber for actuating the control valve, and free exhaust ports for the pressure chambers and being controlled by the distributing valve.

2. In a fluid actuated rock drill, the combination of a cylinder having a piston chamber and a piston therein, a valve chest having distributing and control valve chambers, a distributing valve in the distributing valve chamber to control the distribution of pressure fluid into the piston chamber, a control valve in the control valve chamber, opposed pressure chambers in the distributing valve chamber, inlet passages controlled by the control valve conveying pressure fluid from the control valve chamber to the pressure chambers for actuating the distributing valve and conveying compression from the pressure chambers to the control valve chamber for actuating the control valve, free exhaust ports for the pressure chambers and being controlled by the distributing valve, 2. supply passage for the control valve chamber, and a needle valve for controlling the supply passage.

GEORGE H. FUEHRER. 

